tbi spacer that bolts up on a carb intake
 

please help i have a 350 carb motor thats was in my 80 camaro it was rebuilt a long time ago the car was sitting for a while the engine probably has 15,000 miles it has a holley intake can anyone tell me if i can use the engine without changing the the intake manifold what kind of spacer will i need to bolt up the tbi to carb allso how much hp and torque gain will i get i need the power to pull a landscapeing trailer loaded with equipment the truck is a 88 gmc 1500 with a 350 tbi